Hi. I have a version serious bought of Cyanobacteria running through my tank at the moment. In the 6 years I have been keeping a planted aquarium, I have never had a Cyanobacteria outbreak before!
Some technical specs of my tank first:
6' x 15'' x 18'' (~ 400 litres / 100 gallons)
240 watts NEC tri-phosphor lighting (~ 2.5 wpg)
Eheim 2217 filter
Red Sea CO2 Pro system
100% Seachem flourite substrate
Seachem flourish + Seachem iron dosed Saturday/Wednesday
Potasium Sulphate dosed Saturday/Wednesday
Seachem Nitrogen dosed as needed to keep nitrate 5-10mg/l.
Plants are Ludwigia, Vallisneria, Ambulia, Echinodorous Tenellus, Bacopa Caroliana. And fish of course.
Anyway, here are my initial questions:
1. My understanding is that Cyanobacteria (which I know is a bacteria, not a true algae) is *everywhere*. In the air we breath etc etc. So, I understand that it's spores are always present in an established aquarium, only blooming and choking a tank should some conditions trigger it (hence my next question). Is this correct for a start?
2. What triggers the Cyanobacteria bloom? I've heard that when nitrates bottom out, causing higher plant growth to stop (after all plant tissue stored Nitrogen is used up as well I guess), that this can cause Cyanobacteria to start 'fixing' nitrogen and hence getting a foothold? This would correlate with my findings precisely, my nitrate level did indeed bottom out as I upped my maintenance routine in an attempt to cure a black brush algae problem (another thing to discuss another time).
3. Finally, the obvious, how does one get rid of it? If the extremely low nitrate condition is what triggered it, correcting this would, I guess, prevent it from happening again, but now that the Cyanobacteria has it's foothold, correcting the low nitrate condition, to my mind, won't actually get rid of it? The fact that it is covering the plant leaves will obviously inhibit photosynthesis, so I'm guessing that things just keep getting better and better for the Cyano? My guess is that I need to tip things back in favour for the plants. I have read that either a blackout or anti-biotics will get rid of it - this makes sense to me. I don't see how there could be any other choice with the exception of, theoretically, being able to make the tank larger to accomodate an influx of healthy plants (which can't happen since my tank is already totally occupied with cyano covered plants!). The healthy plants would suck up the nutrients and starve out the cyano. I'm thinking that by using the blackout or antibiotics technique whilst also ensuring that the cyano trigger is removed (i.e. set nitrate to 5-10mg/l), this should do the trick?
Scott.
Some technical specs of my tank first:
6' x 15'' x 18'' (~ 400 litres / 100 gallons)
240 watts NEC tri-phosphor lighting (~ 2.5 wpg)
Eheim 2217 filter
Red Sea CO2 Pro system
100% Seachem flourite substrate
Seachem flourish + Seachem iron dosed Saturday/Wednesday
Potasium Sulphate dosed Saturday/Wednesday
Seachem Nitrogen dosed as needed to keep nitrate 5-10mg/l.
Plants are Ludwigia, Vallisneria, Ambulia, Echinodorous Tenellus, Bacopa Caroliana. And fish of course.
Anyway, here are my initial questions:
1. My understanding is that Cyanobacteria (which I know is a bacteria, not a true algae) is *everywhere*. In the air we breath etc etc. So, I understand that it's spores are always present in an established aquarium, only blooming and choking a tank should some conditions trigger it (hence my next question). Is this correct for a start?
2. What triggers the Cyanobacteria bloom? I've heard that when nitrates bottom out, causing higher plant growth to stop (after all plant tissue stored Nitrogen is used up as well I guess), that this can cause Cyanobacteria to start 'fixing' nitrogen and hence getting a foothold? This would correlate with my findings precisely, my nitrate level did indeed bottom out as I upped my maintenance routine in an attempt to cure a black brush algae problem (another thing to discuss another time).
3. Finally, the obvious, how does one get rid of it? If the extremely low nitrate condition is what triggered it, correcting this would, I guess, prevent it from happening again, but now that the Cyanobacteria has it's foothold, correcting the low nitrate condition, to my mind, won't actually get rid of it? The fact that it is covering the plant leaves will obviously inhibit photosynthesis, so I'm guessing that things just keep getting better and better for the Cyano? My guess is that I need to tip things back in favour for the plants. I have read that either a blackout or anti-biotics will get rid of it - this makes sense to me. I don't see how there could be any other choice with the exception of, theoretically, being able to make the tank larger to accomodate an influx of healthy plants (which can't happen since my tank is already totally occupied with cyano covered plants!). The healthy plants would suck up the nutrients and starve out the cyano. I'm thinking that by using the blackout or antibiotics technique whilst also ensuring that the cyano trigger is removed (i.e. set nitrate to 5-10mg/l), this should do the trick?
Scott.
